Drought Conditions in Maine, 1999-2002: A Historical 

Perspective

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 03-4310
Cover Photograph: St. John River at Ninemile, Maine, September 3, 2002. Photograph courtesy of 

Greg Stewart.
Drought Conditions in Maine, 1999-2002: A Historical 

Perspective

By Pamela J. Lombard

Augusta, Maine

2004

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 03-4310
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

For additional information write to: Copies of this report can be purchased 

from:

U.S. Geological Survey

Information Services

Building 810

Box 25286, Federal Center

Denver, CO 80225-0286

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

District Chief

U.S. Geological Survey

Maine District

196 Whitten Road

Augusta, Maine 04330

http://me.water.usgs.gov
Contents iii

Abstract ................................................................................................................................................................................. 1

Introduction ........................................................................................................................................................................... 1

Purpose and Scope ...................................................................................................................................................... 2

Drought Definition ...................................................................................................................................................... 2

Previous Studies .......................................................................................................................................................... 2

Acknowledgments....................................................................................................................................................... 3

Data Compilation .................................................................................................................................................................. 3

Precipitation Gages ..................................................................................................................................................... 3

Streamflow-Gaging Stations ....................................................................................................................................... 5

Monitoring Wells ........................................................................................................................................................ 5

Drought Conditions in Maine from 1999 to 2002................................................................................................................. 6

Precipitation ................................................................................................................................................................ 6

Surface Water.............................................................................................................................................................. 10

Ground Water.............................................................................................................................................................. 10

Annual Recurrence Intervals of 7-Day Surface-Water Low Flows ............................................................................ 15

Comparison of 1999-2002 Drought to Historical Droughts in Maine .................................................................................. 19

Annual Recurrence Intervals of 7-Day Surface-Water Low Flows ............................................................................ 24

Ground-Water Levels at Middle Dam, Lower Richardson Lake, Maine.................................................................... 25

Interaction among Precipitation, Surface Water, and Ground Water During Drought......................................................... 25

Summary and Conclusions.................................................................................................................................................... 32

References Cited ................................................................................................................................................................... 35

LIST OF FIGURES

1. Map showing location of study area and data-collection sites, Maine...................................................................... 4

2. Graph showing monthly departure from normal precipitation at Caribou Municipal Airport, Maine, 

1999-2003............................................................................................................................................................. 7

3. Graph showing accumulated departure from normal precipitation at Caribou Municipal Airport, 

Maine, 1999-2003................................................................................................................................................. 7

4. Graph showing departure from normal precipitation at Millinocket, Maine, 1999-2003. ........................................ 8

5. Graph showing accumulated departure from normal precipitation at Millinocket, Maine, 1999-2003.................... 8

6. Graph showing departure from normal precipitation at Portland International Jetport, Maine, 1999-2003............. 9

7. Graph showing accumulated departure from normal precipitation at Portland International 

Jetport, Maine, 1999-2003.................................................................................................................................... 9

8. Graph showing comparison of 1999-2003 streamflows to historical mean, maximum, and minimum

streamflows at U.S. Geological Survey streamflow-gaging station 01031500, Piscataquis River 

near Dover-Foxcroft, Maine ................................................................................................................................. 11

9. Graph showing comparison of 1999-2003 streamflows to historical mean, maximum, and minimum 

streamflows at U.S. Geological Survey streamflow-gaging station 01022500, Narraguagus River 

at Cherryfield, Maine ........................................................................................................................................... 12

10. Graph showing comparison of 1999-2003 streamflows to historical mean, maximum, and minimum 

streamflows at U.S. Geological Survey streamflow-gaging station 01054200, Wild River at 

Gilead, Maine ...................................................................................................................................................... 13

11. Graph showing comparison of 1999-2003 streamflows to historical mean, maximum, and minimum 

streamflows at U.S. Geological Survey streamflow-gaging station 01014000, St. John River at 

at Fort Kent, Maine............................................................................................................................................... 14

CONTENTS
iv Drought Conditions in Maine in 1999 - 2002: A Historical Perspective

12. Graph showing comparison of 1999-2003 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S.Geological Survey monitoring 

well OW 1214 (440823070291501), in Sanford, Oxford County, Maine............................................................ 16

13. Graph showing comparison of 1999-2003 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S.Geological Survey monitoring 

well SMW 61 (445148069513301), in Madison, Somerset County, Maine ....................................................... 17

14. Graph showing comparison of 1999-2003 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S.Geological Survey monitoring 

well Y807 (432310070393301), in Sanford, York County, Maine ..................................................................... 18

15. Map showing regional recurrence intervals for 7-day low flows in Maine during 1999 .......................................... 20

16. Map showing regional recurrence intervals for 7-day low flows in Maine during 2000 .......................................... 21

17. Map showing regional recurrence intervals for 7-day low flows in Maine during 2001 .......................................... 22

18. Map showing regional recurrence intervals for 7-day low flows in Maine during 2002 .......................................... 23

19. Map showing 7-day low flow recurrence intervals for seven historical drought periods and 

1999-2002 drought in Maine ............................................................................................................................... 26

20. Graph showing comparison of 1947-50 month-end ground-water levels to historical median,

maximum, and minimum month-end ground-water levels at U.S. Geological Survey companion 

wells OW 400 and OW 400A in Maine (444637070552301 and 443647070552302) ........................................ 28

21. Graph showing comparison of 1952-53 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S. Geological Survey wells 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302).................................................. 28

22. Graph showing comparison of 1955-59 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S. Geological Survey wells 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302).................................................. 29

23. Graph showing comparison of 1963-69 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S. Geological Survey wells 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302).................................................. 29

24. Graph showing comparison of 1978 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S. Geological Survey wells 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302).................................................. 30

25. Graph showing comparison of 1984-88 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S. Geological Survey wells 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302).................................................. 30

26. Graph showing comparison of 1995 month-end ground-water levels to historical median, 

maximum, and minimum month-end ground-water levels at U.S. Geological Survey wells 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302).................................................. 31

27. Graph showing comparison of 1999-2002 month-end ground-water levels to historical median,

maximum, and minimum month-end ground-water levels at U.S. Geological Survey wells 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302).................................................. 31

28. Graph showing precipitation deficits propagated in runoff, soil moisture, streamflow, and ground water 

over time ............................................................................................................................................................... 32

29. Graph showing annual minimum month-end ground-water levels and annual 7-day surface-water lows

plotted with periods of surface-water drought near Middle Dam, Lower Richardson Lake, Maine,

1945-2002............................................................................................................................................................. 33

30. Graph showing precipitation, surface water, and ground water departures from monthly means near

Middle Dam, Lower Richardson Lake, Maine, 1999 -2002................................................................................. 34
Contents v

LIST OF TABLES

1. Low-flow recurrence intervals for historical droughts in Maine from 1938 to 1988, as identified by 

Maloney and Bartlett in the National Water Summary, 1991 ............................................................................... 3

2. National Weather Service precipitation gages used in this study in Maine ................................................................ 5

3. U.S. Geological Survey streamflow-gaging stations used in this study in Maine ...................................................... 5

4. U.S. Geological Survey ground-water wells used in this study in Maine................................................................... 6

5. Station name, location, number, and 7-day low-flow recurrence intervals for individual years 

1999-2002 at select USGS streamflow-gaging stations in Maine......................................................................... 15

6. Approximate recurrence intervals for historical droughts in Maine, 1947-2002........................................................ 24

CONVERSION FACTORS

To convert temperature in degrees Fahrenheit (°F) to degrees Celsius (°C) use the following equation:

°C = 5/9 * (°F - 32)

Multiply By To obtain

inch (in.) 25.4 millimeter

foot (ft) 0.3048 meter

cubic foot per second (ft3/s) 0.02832 cubic meter per second

cubic foot per second per square 

mile (ft3/s)/mi2 0.01094

cubic meter per second per 

square kilometer

Abstract 1

Drought Conditions in Maine, 1999-2002: A Historical Perspective 

by Pamela J. Lombard

ABSTRACT

Hydrologic drought can be defined as reduced 

streamflow, declining ground-water levels, and (or) 

reductions in lake or reservoir levels. Monthly precipitation totals, annual 7-day low-flow surface-water 

recurrence intervals, and month-end ground-water 

levels from drought years 1999-2002 show that 1999-

2002 was the driest period of hydrologic drought in 

more than 50 years of record in Maine. Record lows 

were set in all three data sets at select locations in 

central Maine in April 1999, and in September 2001 

and 2002. Although streamflows recovered to normal 

levels during 2000, ground-water levels in central 

Maine indicate that the drought carried over through 

2000 into 2001 and 2002 in some locations. 

In 2001, annual 7-day low flows with greater 

than 100-year recurrence intervals were recorded in 

central Maine and low flows with up to 75-year recurrence intervals were recorded in coastal areas. In 2002, 

annual 7-day low flows with greater than 100-year 

recurrence intervals were recorded at 4 of 14 stations 

analyzed statewide, placing it as the driest single year 

of hydrologic drought on record. Month-end groundwater levels at one location in central Maine indicate 

that the recent hydrologic drought years were the most 

severe in more than 50 years in that region. The period 

from 1947 to 1950 may have been the only comparable 

period of drought to the 1999-2002 period, in Maine. 

The 1960s drought, although extreme in the far 

northern and far southern regions of the State, was most 

exceptional for its duration from 1963 to 1969.

INTRODUCTION 

Drought is among the most complex and least 

understood of all natural hazards, affecting more 

people than any other natural hazard (American Meteorological Society, 1997). Although drought typically 

is not considered a problem in the humid northeastern 

United States, it is a normal, recurring feature in all 

climatic regimes. Drought is a temporary aberration, 

relative to some long-term (tens of years) average 

condition, as opposed to aridity, which is a permanent 

feature of some regional climates (American Meteorological Society, 1997). Many questions still remain 

concerning the physical mechanisms responsible for 

the onset, persistence, and spatial extent of regional 

hydrologic drought in the northeast because of hydrologic variability and the inherent complexity of hydrologic systems (Bradbury and others, 2002). 

Dry conditions were present in Maine from 1999 

to 2002, with a severe drought in 2001-2002. Most 

U.S.Geological Survey (USGS) monitoring wells, and 

many streamflow-gaging stations, set record lows 

during this period. An estimated 7 percent, or approximately 17,000 private wells in Maine went dry in the 

9 months prior to April 2002 (Maine Emergency 

Management Agency, 2002). Wells in central Maine 

were the most likely to have low water levels. Thirtyfive public water supplies, including eight large 

community systems, were affected severely (Andrews 

Tolman, Maine Drinking Water Program, written 

communication, 2003). Most major surface-water 

reservoirs released water at levels below their regulatory minimum flows, instream flows for aquatic life 

were reduced, and critical summer irrigation was 

limited. Farmers in Maine lost more than 32 million 

dollars in crops in 2001 and 2002, with some wild blueberry growers recording crop losses of 80 to 100 

percent according to a Maine Department of Agriculture water-use survey to which 28 percent of Maine 

farmers responded (Maine Agricultural Water 

Management Advisory Committee, 2003). 

The effects of past droughts nationwide have 

been exacerbated by the absence of preparedness plans 

(American Meteorological Society, 1997). An integral 

part of any preparedness plan would include meteorologic and hydrologic thresholds based on historical 
2 Drought Conditions in Maine, 1999-2002: A Historical Perspective

droughts in the region. During 1999-2002, waterresource professionals, farmers, business owners, and 

others who were concerned with instream flows, 

storage, or ground-water levels lacked the quantitative 

historical information necessary to compare the 

severity of the 1999 to 2002 drought to historical 

droughts, and to assess the potential of drought to stress 

water resources. Because droughts will occur in Maine 

in the future, water-resource professionals will benefit 

from documentation and analysis of the hydrologic 

conditions experienced from 1999 to 2002 in Maine. In 

particular, emergency management workers and 

public-water suppliers in Maine will benefit from this 

information by better understanding the complexity of 

how droughts move through the hydrologic system, 

and thus, be better able to anticipate drought effects. 

Purpose and Scope

The purpose of this report is to document the 

relative regional and historical severity of the dry 

hydrologic conditions experienced from 1999 to 2002, 

and to provide information regarding the occurrence 

and persistence of droughts in Maine. This report 

includes a comparison of 1999-2002 daily mean 

streamflows, month-end ground-water levels, and total 

monthly precipitation values to historical statistics at 

select stations. The interaction among precipitation, 

surface water, and ground water, the annual 7-day 

surface-water low-flow recurrence intervals for this 

drought period and for historical droughts, and a 

comparison of month-end ground-water levels to 

ground-water statistics for historical droughts also are 

examined. 

Drought Definition

Droughts can be measured or defined on the 

basis of a wide variety of parameters including precipitation deficits, streamflows, ground-water levels, soil 

moisture, and economic impacts. The relation among 

the intensity, duration, and spatial and temporal extent 

of these parameters defines many different types of 

events, all of which may be considered droughts. For 

example, a growing season with no rain in the northern 

region of the State would be characterized differently 

than a statewide, multi-year period with below-average 

precipitation, but both could be considered droughts. 

Although drought can be defined strictly as a 

percentage of normal precipitation, it is more often 

defined as a period of moisture deficit sufficient to 

have some adverse effect on the social or economic 

activity of a region (Changnon, 1980; Paulson and 

others, 1991). The integration of multiple definitions 

into a combined measure of drought has been problematic in the past for natural resource managers. The 

many definitions of drought make it difficult to declare 

the beginning or end of a drought or assess its severity 

during a drought period. 

The American Meteorological Society groups 

drought into four types including climatologic drought, 

agricultural drought, hydrologic drought, and socioeconomic drought (American Meteorological Society, 

1997). Climatologic drought often is defined by a 

threshold precipitation deficit or a ratio of actual 

precipitation to normal precipitation. Agricultural 

drought links climatologic drought to agricultural 

effects and is largely the result of a deficit of soil moisture. Hydrologic drought is defined as reduced streamflow, declining ground-water levels, and (or) 

reductions in lake or storage levels. Socioeconomic 

drought associates the supply and demand of some 

economic good with the elements of climatologic, agricultural, and (or) hydrologic drought (American Meteorological Society, 1997). These types of drought 

usually take place simultaneously; however, hydrologic droughts typically are out of phase with or lag 

climatologic and agricultural droughts. Meteorologic 

elements, such as temperature, wind, and relative 

humidity, can aggravate the severity and the effects of 

drought (American Meteorological Society, 1997). 

Although various aspects of all four drought types 

defined here occurred in Maine from 1999 to 2002, this 

report primarily documents the characteristics of the 

hydrologic drought and how the climatologic drought 

contributed to it. 

Previous Studies

There is very little documentation of historical 

droughts in Maine. In 1991, the USGS defined multiyear historical droughts in each state of the United 

States, and calculated their recurrence intervals in a 

National Water Summary on floods and droughts 

(Paulson and others, 1991). Drought periods identified 

for the Maine Water Summary are listed in table 1 

(Maloney and Bartlett, 1991): 
Data Compilation 3

Table 1. Low-flow recurrence intervals for historical 

droughts in Maine from 1938 to 1988, as identified by 

Maloney and Bartlett in the National Water Summary, 

1991 [Low-flow recurrence interval, the average 

interval of time within which streamflow will be less 

than a particular value; >, greater than] 

The recurrence intervals for the droughts in table 

1 were calculated on the basis of the cumulative departure from mean monthly streamflows. This method is 

described in the introduction to State summaries of 

floods and droughts in the National Water Summary 

(Jordan and Jennings, 1991). The intensity of the 

drought was taken into account, but the duration was 

not; droughts that varied in duration from 1 year to 6 

years were ranked on the same scale. This method may 

be appropriate for identifying multi-year periods of 

drought, or assigning recurrence intervals to total water 

deficits in systems that depend on reservoirs such as in 

the western United States, but it is not appropriate for 

eastern States except in the most approximate terms. 

This is because drought in the eastern United States 

may depend on the timing of precipitation as much as 

on the total amount of precipitation. 

Resource managers in the northeastern United 

States often use national indices to assess regional 

conditions despite that these indices may be more 

appropriate for nationwide water-status monitoring 

(Skaggs, 1975). Often, the national indices fail to give 

those affected by the drought or those who make policy 

a local basis for evaluation and action (Russell, and 

others, 1970). Even different user groups within a 

region may experience drought periods in different 

ways. For example, in the first year of a drought, 

farmers can face severe shortages while public water 

suppliers may not experience a deficit. Likewise, in 

subsequent years of a drought, agriculture may recover 

because of seasonal rains, but the hydrologic indices 

such as ground- water levels may take an additional 

year to recover. 

Acknowledgements 

The author would like to acknowledge Joseph 

Nielsen, USGS, for providing technical guidance, 

Sarah Canon, USGS, for her ground-water data analyses, and USGS Hydrologic technicians in the Maine 

District for over 100 years of data collection.

DATA COMPILATION 

Statewide hydrologic drought conditions in 

Maine from 1999 to 2002 were examined using data 

from National Weather Service precipitation stations, 

USGS streamflow-gaging stations, and USGS groundwater wells at select locations around the State (fig. 1). 

Stations were chosen on the basis of their length of 

record and their location. The goal in all cases was to 

use an even distribution of stations around the State 

with a sufficient period of record to give historical 

perspective. Although data are presented through 

2003, precipitation data after December 2002 and 

ground-water and surface-water data after September 

2002 are considered preliminary and are subject to 

change. 

Precipitation Gages 

Four precipitation stations were used in this 

study: Caribou Municipal Airport (National Weather 

Service Station number 171175) in northern Maine, 

Millinocket (station 175304) and Middle Dam (station 

175261) in central Maine, and Portland International 

Jetport (station 176905) in southern Maine (fig. 1, table 

2). Monthly totals are National Weather Service data 

downloaded off of the Northeast Regional Climate 

Center’s Web site (http://climod.nrcc.cornell.edu). All 

National Weather Service data prior to January 2003 

are final; data from January to May 2003, however, are 

preliminary and subject to change. 

 Although the periods of record at these stations 

range from 55 to 83 years, monthly precipitation data 

from 1999 to 2002 were plotted against National 

Weather Service 30-year monthly normals (1971-

2000) (U.S. Department of Commerce, National 

Oceanic and Atmospheric Administration, 2000). 

Dates Area Affected

Low-Flow Recurrence Interval 

(years)

1938-43 Western areas 15 to >30

1947-50 South-central areas 15 to >30

1955-57 Nearly entire state 15 to >30

1963-69 Statewide >30

1984-88 Statewide 15 to >30
4 Drought Conditions in Maine, 1999-2002: A Historical Perspective

 

AROOSTOOK

PISCATAQUIS

SOMERSET

PENOBSCOT

WASHINGTON

HANCOCK

WALDO

KNOX

LINCOLN

KENNEBEC

FRANKLIN

OXFORD

ANDROSCOGGIN

CUMBERLAND

YORK

44 SAGADAHOC o

43 o

o

o 45

71

46 o

67 o

70 o

69 o 68 o

47 o

0

0

40

50

80 MILES

100 KILOMETERS

KNOX

EXPLANATION

U.S. Geological Survey streamflow-gaging

station and identification number

U.S. Geological Survey monitoring well

and local identification number

National Weather Service precipitation gage

and name

County boundary & name

01014000

01014000

01010000

01015800

01030500

01022500

01031500

01052500 01047000

01055000

01057000

01060000

01038000

01064500

01054200

+

+

+

+

+

SMW 61

SMW 61

Millinocket

OW 1214

YW 807

OW 400A/OW 400

Portland

International

Jetport

Middle Dam

Millinocket

Caribou Municipal Airport

MAINE

Base from U.S. Geological Survey

digital files, scale 1:2,000,000

projection UTM, zone 19

CANADA

NEW HAMPSHIRE

Atlantic Ocean

CANADA

Figure 1. Location of study area and data-collection sites, Maine. 
Data Compilation 5

Streamflow-Gaging Stations 

Data were compiled from 14 USGS streamflowgaging stations around the State (fig. 1, table 3). These 

stations were chosen on the basis of their geographical 

diversity, period of record, and lack of appreciable 

regulation. Periods of record range from 37 to 98 years 

with an average of 68 years. Mean daily flows are 

published annually in USGS water-resources data 

reports, the most recent of which is Stewart and others 

(2003). 

Low-flow statistics used in this report are 

defined in the Annual Data Reports for Maine (Stewart 

and others, 2003) and are as follows: the annual mean 

discharge refers to the arithmetic mean of the individual daily mean discharges, the daily mean minimum 

flow is the lowest daily mean for that day over the 

period of record, the lowest daily mean flow is the 

minimum daily mean discharge for any day during the 

period of record, the instantaneous low flow is the 

minimum instantaneous discharge occurring during the 

period of record, and the minimum monthly mean flow 

is the minimum mean flow for that month over the 

period of record. The 7-day annual low flow is the 

mean discharge of the lowest 7 consecutive days during 

a water year. 

Monitoring Wells 

USGS monitoring wells used to determine the 

affect of the drought on ground-water levels were; local 

number Y807 (USGS number 432310070393301) in 

York County, local numbers OW 1214 

(440823070291501), OW 400 (444637070552301), 

and OW400A (443647070552302) in Oxford county, 

and local number SMW 61 (445148069513301) in 

Somerset County (fig.1, table 4). 

 Table 2. National Weather Service precipitation gages used in this study in Maine

National Weather Service 

Station Number Name/location Period of record

171175 Caribou Municipal Airport, Maine 1939-2003

175261 Middle Dam, Lower Richardson Lake, Maine 1948-2003

175304 Millinocket, Maine 1948-2003

176905 Portland International Jetport, Maine 1920-2003

Table 3. U.S. Geological Survey streamflow-gaging stations used in this study in Maine

 U.S. Geological 

Survey 

station number

U.S. Geological Survey Station Name Period of record Drainage area 

(square miles)

Map identification 

number 

(fig. 19) 

01010000 St. John River at Ninemile Bridge, Maine 1952-2003 1,341 A

01014000 St. John River below Fish River, at Fort Kent, Maine 1928-2003 5,665 B

01015800 Aroostook River near Masardis, Maine 1958-2003 892 C

01022500 Narraguagus River at Cherryfield, Maine 1949-2003 227 D

01030500 Mattawamkeag River near Mattawamkeag, Maine 1936-2003 1,418 E

01031500 Piscataquis River near Dover-Foxcroft, Maine 1904-2003 298 F

01038000 Sheepscot River at North Whitefield, Maine 1940-2003 145 G 

01047000 Carrabassett River near North Anson, Maine 1904-2003 353 H

01052500 Diamond River near Wentworth Location, New Hampshire 1942-2003 152 I

01054200 Wild River at Gilead, Maine 1965-2003 69.6 J

01055000 Swift River near Roxbury, Maine 1930-2003 96.9 K

01057000 Little Androscoggin River near South Paris, Maine 1915-2003 73.5 L

01060000 Royal River at Yarmouth, Maine 1951-2003 141 M

01064500 Saco River near Conway, New Hampshire 1905-2003 385 N
6 Drought Conditions in Maine, 1999-2002: A Historical Perspective

Data from these monitoring wells are a combination of continuous- recorder data and month-end waterlevel readings. Although continuous record is available 

since 1989 for OW1214 and YW807, 1999 for 

SMW61, and 2001 for O400A, month-end values were 

used in all cases to compare conditions from 1999 

through 2003 with historical statistics, for which only 

month-end data are available. 

In most cases, month-end ground-water levels 

represent a single water level recorded some time 

between the 20th and the end of the month. For cases 

in which more than one record is available during this 

period, the record that is closest to the end of the month 

is used. For continuous record, this is the water level 

recorded at noon on the last day of the month. Well 

OW400A was created as a companion well for 

OW400, and thus the data from these two wells were 

combined. Well numbers OW400 and OW400A have 

periods of record from 1944 to 1992 and 1989 to 2003, 

respectively, giving them a period of overlap from 

1989 to 1992 from which a regression equation was 

derived. Month-end water levels from discontinued 

well OW 400 were adjusted on the basis of this regression equation so that analyses could be performed on 

the combined period of record of 57 years (2003 was 

not used in the analyses). Month-end data from these 

companion wells represent averages of all records from 

the 20th until the end of the month. Prior to 2001, this 

value is an average of from 2 to 3 daily readings, which 

were taken every fifth day. After 2001, this value is an 

average of the continuous values from the 20th until the 

end of the month. 

DROUGHT CONDITIONS IN MAINE FROM 1999 TO 

2002 

The description of drought years 1999 through 

2002 includes both the amount and the timing of 

monthly precipitation, 7-day average streamflows, and 

month-end ground-water levels during this time period. 

Precipitation

Caribou Municipal Airport was within the 

normal range for monthly precipitation (within 2 in. of 

the 30-year monthly normals) in 1999 and 2000 (fig. 

2). The only appreciable deviation from normal was in 

September 1999 with 8.8 in. of precipitation (5.5 in. 

above normal). Accumulated observed rainfall 

dropped below accumulated normal rainfall in the 

spring of 2001 and stayed below normal throughout the 

rest of 2001 and all of 2002 (fig. 3). August 2002, with 

only 0.55 in. of precipitation was 3.6 in. below normal, 

leading to one of the driest Septembers on record at 

various streamflow stations in northern Maine. 

Total precipitation of less than 1 in. in April 1999 

(2.6 in. below normal), was the lowest April rainfall on 

record (1948-2002) at Millinocket. In September 

1999, however, Millinocket received 7.5 in. of rain (3.8 

in. above normal) putting the total precipitation for the 

year in the normal range. This value indicates that the 

precipitation deficit and the resulting drought was more 

a problem of the timing of precipitation than of the total 

amount of precipitation during 1999 (fig. 4). Accumulated observed rainfall from 1999-2002 departed from 

accumulated normal rainfalls in January 2001 (fig. 5). 

Nineteen out of 24 months in 2001 and 2002 received 

normal or below-normal precipitation with a 2-year 

total accumulated departure from normal of 19 in. 

August 2002, with 0.7 in. of rain (3.3 in. below 

normal), was the lowest August precipitation on record 

at Millinocket. 

Portland had rainfall patterns similar to Millinocket from 1999 to 2002 . Portland received 0.3 in. of 

precipitation in April 1999 (4.0 in. below normal) (fig. 

6). September 1999 had record high amounts of

Table 4. U.S. Geological Survey ground-water wells used in this study in Maine 

Local well 

number 

U.S. Geological 

Survey well number Local name, location Description of Aquifer Period of 

record

Y807 432310070393301 South Sanford, York County, Maine Ice-contact glaciofluvial deposits 1988-2003

OW1214 440823070291501 Oxford, Oxford County, Maine Stratified sand 1980-2003

SMW61 445148069513301 Madison, Somerset County, Maine Glaciomarine sand and silt 1985-2003

OW400 444637070552301 Middle Dam, Oxford County, Maine Glacial till 1944-1992

OW400A 443647070552302 Middle Dam, Oxford County,Maine Glacial till 1989-2003
Drought Conditions in Maine from 1999 to 2002 7

-6-4-2

0246

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

Jul-00

Sep-00

Nov-00

Jan-01

Mar-01

May-01

Jul-01

Sep-01

Nov-01

Jan-02

Mar-02

May-02

Jul-02

Sep-02

PRECIPITATION DEPARTURE FROM NORMAL,

IN INCHES

0

20406080

100120140160180

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

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Jul-01

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May-02

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Sep-02

ACCUMULATED PRECIPITATION, IN INCHES Normal Obse rved

ACCUMULATED PRECIPITATION, IN INCHES

MONTH AND YEAR

MONTH AND YEAR

PRECIPITATION DEPARTURE FROM NORMAL,

IN INCHES

Figure 2. Monthly departure from normal precipitation at Caribou Municipal Airport, Maine, 1999-2003. [National Weather Service Station n

based on National Weather Service observations, 1971-2000]

Figure 3. Accumulated departure from normal precipitation at Caribou Municipal Airport, Maine, 1999-2003. [National Weather Service St

are based on National Weather Service observations, 1971-2000]
8 Drought Conditions in Maine, 1999-2002: A Historical Perspective -4-3-2-1

012345

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

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Jul-00

Sep-00

Nov-00

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Mar-01

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Jul-01

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PRECIPITATION DEPARTURE FROM

NORMAL, IN INCHES 020406080 100 120 140 160 180 200

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

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May-02

ACCUMULATED PRECIPITATION, IN INCHES Normal Observed

ACCUMULATED PRECIPITATION, IN INCHES

MONTH AND YEAR

MONTH AND YEAR

PRECIPITATION DEPARTURE FROM NORMAL,

IN INCHES

Figure 4. Departure from normal precipitation at Millinocket, Maine, 1999-2003. [National Weather Service Station number 175304; no

Weather Service observations, 1971-2000]

Figure 5. Accumulated departure from normal precipitation at Millinocket, Maine, 1999-2003. [National Weather Service Station num

on National Weather Service observations, 1971-2000]
Drought Conditions in Maine from 1999 to 2002 9

-5-3-1

135

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

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Mar-01

May-01

Jul-01

Sep-01

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PRECIPITATION DEPARTURE FROM NORMAL,

IN INCHES 050 100 150 200 250

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

Jul-00

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Nov-00

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Jul-02

ACCUMULATED PRECIPITATION, IN INCHES Normal Observed

ACCUMULATED PRECIPITATION, IN INCHES

MONTH AND YEAR

MONTH AND YEAR

PRECIPITATION DEPARTURE FROM NORMAL,

IN INCHES

Figure 6. Departure from normal precipitation at Portland International Jetport, Maine, 1999-2003. [National Weather Service Station number 1

Weather Service observations, 1971-2000]

Figure 7. Accumulated departure from normal precipitation at Portland International Jetport, Maine, 1999-2003. [National Weather Service Stati

National Weather Service observations, 1971-2000]
10 Drought Conditions in Maine, 1999-2002: A Historical Perspective

precipitation resulting from two hurricanes during that 

month totaling 8.8 in. (5.4 in. above normal). Sixteen 

of 24 months received normal or below normal precipitation during 2001 and 2002. Accumulated observed 

precipitation departed from accumulated normal rainfalls in 2000 and stayed below normal through May 

2003 (fig.7). 

Surface Water

Seven-day running averages of daily discharge 

from January 1999 to May 2003 were plotted against 7-

day running average minimum-, maximum-, and meanstatistics for the period of record at each station. 

Streamflow in the central and eastern parts of the State 

was below normal (below the 25th quartile) during 

1999, setting record-minimum flows at some locations 

in the spring of that year. Streamflows in central and 

coastal Maine indicated above normal streamflows 

(above the 75th quartile) in the spring of 2000, but then 

were at or below normal throughout the remainder of 

the year. In 2001, record-low conditions were recorded 

in many central and coastal locations. In 2002, the 

drought continued to be severe in central Maine. 

Drought conditions spread north and west but lessened 

near the coast. 

The Piscataquis River near Dover-Foxcroft in 

central Maine (USGS station 01031500) recorded 

extremely low streamflow relative to seasonal normals 

in the spring of 1999, and in 2001 and 2002, setting 

new daily mean minimum streamflow records during 

some days in April and May 1999, July through 

September 2001, and in August and September 2002 

(fig. 8). Streamflow came close to the lowest daily 

mean flow of 5.0 ft3/s, set in 1905, with a flow of 8.6 

ft3/s both on September 16, 2001, and on September 

13, 2002. A record minimum August mean streamflow 

of 14.6 ft3/s was set at this station in August 2001. 

In coastal Maine, the Narraguagus River at Cherryfield (USGS station 01022500) had a record low, 

annual mean low flow in 2001 with a flow of 256 ft3

/s. 

The station also had a record low 7-day low flow of 20 

ft3/s in September 2001. The Narraguagus River at 

Cherryfield set record low daily mean flows in April, 

May, August, September 1999; May, June, and 

August-December 2001; and January 2002. The station 

recorded monthly mean low flow records in November 

2001 and January 2002. Streamflow returned to 

normal conditions at the end of 2002 (fig. 9). 

The hydrologic drought in northern and western 

Maine was not as extreme in 1999-2001, but became 

quite severe in 2002. In September 2002, the Wild 

River at Gilead (USGS station 01054200) set records 

for the lowest daily mean and the lowest annual 7-day 

minimum with flows of 6.1 ft3

/s, and 7.1 ft3/s respectively (fig. 10). The instantaneous low flow was a 

record low of 6.0 ft3

/s on September 10, 2002. The 

Swift River near Roxbury (USGS station 01055000) 

also set records for the lowest daily mean and the 

lowest annual 7-day minimum with flows of 2.9 ft3

/s, 

and 3.4 ft3/s, respectively, in September 2002. The 

instantaneous low flow of record, 2.7 ft3

/s, also was 

recorded on September 10, 2002. A monthly mean 

flow of 9.66 ft3/s in August 2002 was the lowest 

recorded August mean flow. 

The St. John River in northern Maine was 

extremely low in all locations in September 2002. On 

September 10, 2002, record instantaneous low flows 

and daily mean low flows were set at Ninemile Bridge 

(USGS station 01010000). The St. John River below 

Fish River at Fort Kent (station number 01014000), 

had a record low September mean flow of 893 ft3/s in 

2002 (fig. 11). 

Surface-water levels were low in southern Maine 

during both 2001 and 2002, but were not as extreme as 

in other parts of the State. The Royal River at 

Yarmouth (station number 01060000), with 53 years 

of record had a record low October mean flow of 30.5 

ft3

/s in 2001 while the Saco River near Conway, N.H. 

(USGS station 01064500) with 73 years of record had 

a record August mean flow of 120 ft3/s in 2001. 

Ground Water 

Month-end water levels from January 1999 to 

May 2003 were plotted against ground-water statistics, 

including the maximum, minimum, median, 25th and 

75th quartiles based on the period of record at each 

station. In most cases, month-end ground-water levels 

were in the normal range (between the 25th and 75th 

quartiles) for most of 1999 and 2000 and were not 

consistently below normal until 2001 and 2002. 

Centrally located USGS well OW 1214 had normal 

ground-water levels from the spring of 1999 through 

the end of 2000, except in September 1999 when it 

reached record highs. Ground-water levels in this 

Oxford well started dropping in the fall of 2001 

compared to normal fall levels, and attained record 

month-end lows from November 2001 through
Drought Conditions in Maine from 1999 to 2002 11

1

10

100

1,000

10,000

100,000

Jan-99

Mar-99

May-99

J ul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

J ul-00

Sep-00

Nov-00

Jan-01

Mar-01

May-01

J ul-01

Sep-01

Nov-01

Jan-02

Mar-02

May-02

J ul-02

Sep-02

MONTHANDYEAR

STREAMFLOW, IN C U BIC FEET PER SECO N D

Minimum, Mean, Maximum1999-2003

Figure 8. Comparison of 1999-2003 streamflows to historical mean, maximum, and minimum streamflows at U.S. Geological Survey streamflow-

River near Dover-Foxcroft, Maine. [streamflows are 7-day running averages of daily minimum, mean and maximum streamflows over the period of 

daily mean flows from 1999-2003; historical period is 1904-98; data from October 1, 2002, through May 31, 2003, are provisional and subject to ch
12 Drought Conditions in Maine, 1999-2002: A Historical Perspective

10

100

1,000

10,000

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

Jul-00

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Nov-00

Jan-01

Mar-01

May-01

Jul-01

Sep-01

Nov-01

Jan-02

Mar-02

May-02

Jul-02

Sep-02

MONTH AND YEAR

STREAMFLOW, IN CUBIC FEET PER SECOND

Minimum, Mean, Maximum1999-2003

Figure 9. Comparison of 1999-2003 streamflows to historical mean, maximum, and minimum streamflows at U.S. Geological Survey streamflow-g

Narraguagus River at Cherryfield, Maine. [streamflows are 7-day running averages of daily minimum, mean and maximum streamflows over the pe

averages of daily mean flows from 1999-2003; historical period is 1949-98; data from October 1, 2002, through May 31, 2003, are provisional and su
Drought Conditions in Maine from 1999 to 2002 13

1

10

100

1,000

10,000

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

Jul-00

Sep-00

Nov-00

Jan-01

Mar-01

May-01

Jul-01

Sep-01

Nov-01

Jan-02

Mar-02

May-02

Jul-02

Sep-02

MONTH AND YEAR

STREAMFLOW, IN CUBIC FEET PER SECOND

Minimum, Mean, Maximum1999-2003

Figure 10. Comparison of 1999-2003 streamflows to historical mean, maximum, and minimum streamflows at U.S. Geological Survey streamf

Wild River at Gilead, Maine. [streamflows are 7-day running averages of daily minimum, mean and maximum streamflows over the period of rec

of daily mean flows from 1999-2003; historical period is 1965-98; data from October 1, 2002, through May 31, 2003, are provisional and subject 
14 Drought Conditions in Maine, 1999-2002: A Historical Perspective

100

1,000

10,000

100,000

1,000,000

Jan-99

Mar-99

May-99

Jul-99

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Nov-99

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Mar-00

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Sep-00

Nov-00

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Nov-01

Jan-02

Mar-02

May-02

Jul-02

M ONTH AND YEAR

STREAMFLOW, IN CUBIC FEET PER SECOND

Minim um, Mean, Maxim um1999-2003

Figure 11. Comparison of 1999-2003 streamflows to historical mean, maximum, and minimum streamflows at U.S. Geological Survey streamflow-

River at Fort Kent, Maine. [streamflows are 7-day running averages of daily minimum, mean and maximum streamflows over the period of record, mean flows from 1999-2003; historical period is 1928-98; data from October 1, 2002, through May 31, 2003, are provisional and subject to change] 
Drought Conditions in Maine from 1999 to 2002 15

February 2002. Levels stayed below normal through 

May 2003 (fig. 12).

In central Maine, USGS well number SMW 61 

in Madison had record low ground-water levels in May 

through August 1999, October 2001 through March 

2002, and August 2002 through May 2003 (fig. 13). 

Levels were not in the normal range during 2001 or 

2002, and had yet to recover by the end of the study 

period in May 2003. 

USGS well Y807 in York County had normal 

ground-water levels from the spring of 1999 through 

the fall of 2000. Month-end ground-water levels were 

the lowest on record for every month from December 

2001 through November 2002 (fig. 14). 

Annual Recurrence Intervals of 7-Day SurfaceWater Low Flows

Drought usually is defined subjectively or by 

public perception. In order for water-resource 

managers to characterize a drought objectively, and 

place it into historical context, objective parameters 

must be analyzed. Although droughts can be defined 

by the intensity and/or duration of a number of 

different parameters, annual 7-day surface-water low 

flows were used in this report to establish recurrence 

intervals for individual drought years. The annual 7-

day low flow is useful in assessing an individual year 

of drought because it describes a sustained period of 

low flow. 

The 7-day x-year low flow is the annual 

minimum 7-day consecutive average streamflow that is 

equaled or exceeded on average every x number of 

years (where x is the recurrence interval) (Maidment, 

1993). The 7-day x-year low flow often is used for 

regulation purposes, and is familiar to water-resource 

managers. The 7Q10 or “7-day 10-year low flow” is 

the most commonly reported statistic for low-flow 

analyses (Helsel and Hirsch, 1992). Although each 

year is considered independently when calculating 7-

day low flows, the data set consisting of the annual 7-

day low flows over the period of record is likely to 

show serial correlation. This serial correlation could 

become an issue in a long-term statistical analysis, but 

is acceptable here so long as it is acknowledged when 

examining the 7-day low flows over time. The drawback of using annual 7-day low flows to examine 

drought is that it does not characterize the overall 

severity of a multi-year drought, but rather characterizes the individual years that make up that drought. 

Table 5. Station name, location, number, and 7-day low-flow recurrence intervals for individual years 1999-2002 at 

select USGS streamflow-gaging stations in Maine [<, less than; >, greater than] 

U.S. Geological Survey 

station number Station name

7-day low-flow recurrence interval 

(years)

1999 2000 2001 2002

01010000 St. John at Ninemile,Maine < 10 < 10 20 >100

01014000 St. John River at Fort Kent, Maine < 10 < 10 10 55

01015800 Aroostook River near Masardis, Maine < 10 < 10 15 < 10

01022500 Narraguagus River at Cherryfield, Maine 40 < 10 65 10

01030500 Mattawamkeag River near Mattawamkeag, Maine < 10 < 10 10 15

01031500 Piscataquis River near Dover Foxcroft, Maine 30 < 10 >100 >100

01038000 Sheepscot River at North Whitefield, Maine < 10 < 10 10 < 10

01047000 Carrabassett River near North Anson, Maine 30 < 10 30 >100

01052500 Diamond River near Wentworth Location, N.H. < 10 < 10 < 10 40

01054200 Wild River at Gilead, Maine < 10 < 10 30 75

01055000 Swift River near Roxbury, Maine 60 < 10 45 >100

01057000 Little Androscoggin River near South Paris, Maine < 10 < 10 60 40

01060000 Royal River at Yarmouth, Maine <10 < 10 35 35

01064500 Saco River near Conway, N.H. < 10 < 10 35 30
16 Drought Conditions in Maine, 1999-2002: A Historical Perspective

456789

101112

Jan-99

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Jul-00

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Mar-01

May-01

Jul-01

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Nov-01

Jan-02

Mar-02

May-02

Jul-02

WATER LEVEL, IN FEET BELOW LAND SURFACE 1999-2003

Median25th and 75th quartilesMonthly record high/low

MONTH AND YEAR

WATER LEVEL, IN FEET BELOW LAND SURFACE

Figure 12. Comparison of 1999-2003 month-end ground-water levels to historical median, maximum, and minimum month-end ground-water le

monitoring well OW 1214 (440823070291501), in Oxford, Oxford County, Maine. [historical period of record is 1980-98]
Drought Conditions in Maine from 1999 to 2002 17

68

1012141618

Jan-99

Mar-99

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Jul-99

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Nov-99

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May-00

Jul-00

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Mar-01

May-01

Jul-01

Sep-01

Nov-01

Jan-02

Mar-02

May-02

Jul-02

WATER LEVEL, IN FEET BELOW LAND SURFACE 1999-2003 Monthly record high/low Median

25th and 75th quartiles

MONTH AND YEAR

WATER LEVEL, IN FEET BELOW LAND SURFACE

Figure 13. Comparison of 1999-2003 month-end ground-water levels to historical median, maximum, and minimum month-end ground-water l

monitoring well SMW 61 (445148069513301), in Madison, Somerset County, Maine. [historical period of record is 1985-98]
18 Drought Conditions in Maine, 1999-2002: A Historical Perspective 14151617181920

212223

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

Jul-00

Sep-00

Nov-00

Jan-01

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May-01

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Mar-02

May-02

Jul-02

WATER LEVEL, IN FEET BELOW LAND SURFACE 1999-2003 Monthly record high/low Median 25th and 75th quartile

MONTH AND YEAR

WATER LEVEL, IN FEET BELOW LAND SURFACE

Figure 14. Comparison of 1999-2003 month-end ground-water levels to historical median, maximum, and minimum month-end ground-water l

monitoring well Y807 (432310070393301), in Sanford, York County, Maine. [historical period of record is 1988-98] 
Comparison of 1999-2002 Drought to Historical Droughts in Maine 19

The frequency of occurrence or recurrence 

interval is the average length of time between two 

events of a given magnitude and duration. The recurrence interval describes how likely an event is, but does 

not describe when it may occur. Recurrence intervals 

can be calculated for selected time scales and durations. The recurrence interval for the annual 7-day low 

flow may vary appreciably from the recurrence interval 

for the 90-day low flow or from the recurrence interval 

of a multi-year surface-water drought of which it is a 

part. 

It requires a sustained period of below normal 

precipitation to have an annual 7-day low flow with a 

large recurrence interval, making it a good indicator of 

low ground water and surface-water levels, or hydrologic drought. Recurrence intervals calculated in table 

5 are based on annual 7-day low flows at USGS streamflow-gaging stations in Maine with 37 to 98 years of 

record. The historical period used to conduct the lowflow frequency analysis (Maidment, 1993) went 

through year 2000 in all cases. Recurrence intervals 

were mapped to determine approximate regional recurrence intervals for individual drought years from 1999 

to 2002 (figs. 15-18). These maps show how the 

drought progressed from 1999 to 2002. 

The drought began in central Maine in 1999 with 

7-day annual low-flow recurrence intervals from less 

than 10 to 60 years (fig. 15). The centrally located 

streamflow-gaging stations recovered in 2000 when 

recurrence intervals were less than 10 in all locations 

across the State (fig. 16). The central region of the 

State, which had the driest conditions in 1999, was the 

same region that had the most severe drought in 2001 

The recurrence intervals of 7-day annual low flows at 

centrally located streamflow-gaging stations increased 

to greater than 100 years in 2001 (fig. 17). Southern 

and coastal regions of the State had recurrence intervals 

as high as 60 years in 2001 whereas the northern region 

had recurrence intervals from 10 to 20 years in 2001. 

The hydrologic drought spread west and north in 2002 

so that much of the State had up to 100-year recurrence 

intervals at some time during this 4-year period. 

Coastal regions began to recover in 2002 (fig. 18). The 

central region progressed from recurrence intervals of 

from 10 to 60 in 1999 to from 60 to greater than 100 in 

2001, and northern and southern regions progressed 

from less than 10 to from 10 to 60 over this same time 

period. 

COMPARISON OF 1999-2002 DROUGHT TO HISTORICAL DROUGHTS IN MAINE 

Multi-year drought periods usually are identified 

in drought analyses. An objective analysis of these 

multi-year periods is difficult because the range of 

intensities and durations are difficult to rank on the 

same scale. As with the analysis of drought conditions 

from 1999 to 2002, the recurrence interval of the 7-day 

surface-water low flow is used to define the severity of 

individual years during historical drought periods. 

These recurrence intervals then are placed in the 

context of the multi-year drought periods. 

Drought periods identified for Maine in the 

National Water Summary on floods and droughts were 

used for this report (table 1) (Maloney, T.J., and W.P. 

Bartlett Jr., 1991). Additionally, drought years 1952-

53 and 1978 were added because they had 7-day lowflow annual recurrence intervals of up to 90 years and 

40 years, respectively. The period of 1955-57, identified in the National Water Summary, was expanded 

here to 1955-1959 because 1959 had a recurrence 

interval of 85 years in the southern part of the State. 

Droughts in 1995 and 1999-2002, which occurred after 

the publication of the National Water Summary were 

added here as some of the worst drought years on 

record on the basis of the 7-day annual low flows. The 

drought from 1938 to 1943 was identified in the 

National Water Summary, but is not included here 

because most of the stations do not have sufficient 

period of record to include it. 

A total of eight historical drought periods were 

determined in this analysis, including 29 out of a potential 57 years from 1947 to 2002. There are two reasons 

that over half the period from 1947 to 2002 is included 

in this analysis. Three of these periods, or a total of 12 

years, were regional droughts, and thus, no one part of 

the State had drought during all of these periods. 

Secondly, hydrologic drought includes both surfacewater drought and ground-water drought, and groundwater drought tends to lag surface-water drought by up 

to a year. This lag means that each drought period can 

include individual years in the middle and up to one 

year at the end during which surface water is at or 

above normal, but ground water still is recovering. 

Individual years 1958, 1967, 1986 and 2000 in the 

middle of drought periods, and 1950, 1969 and 1988 at 

the end of drought periods do not have 7-day low 

surface-water recurrence intervals greater than 20 years 

at any stations in the State. These years are included as
20 Drought Conditions in Maine, 1999-2002: A Historical Perspective

44 o

43 o

o

o 45

71

46 o

67 o

70 o

69 o 68 o

47 o

0

0

40

50

80 MILES

100 KILOMETERS

EXPLANATION

01014000 Streamflow-gaging station and identification

number. Lower number is recurrence interval,

in years, for 7-day low flows during 1999

[<, less than]

Regional recurrence interval

<10

01047000

<10

01014000

<10

01010000

01015800

<10

<10

01030500

40

01022500

30

01031500

30

60

<10

01052500

01055000

<10

01057000

<10

<10

01060000

01038000

<10

<10

01064500

01054200

Base from U.S. Geological Survey

digital files, scale 1:2,000,000

projection UTM, zone 19

10-60

<10

<10

10

CANADA

NEW HAMPSHIRE

CANADA

ATLANTIC OCEAN

Figure 15. Regional recurrence intervals for 7-day low flows in Maine during 1999.
Comparison of 1999-2002 Drought to Historical Droughts in Maine 21

44 o

43 o

o

o 45

71

46 o

67 o

70 o

69 o 68 o

47 o

0

0

40

50

80 MILES

100 KILOMETERS

EXPLANATION

Streamflow-gaging station and identification

number. Lower number is recurrence interval,

in years, for 7-day low flows during 2000

[<, less than]

Regional recurrence interval

01014000

<10

<10

01014000

<10

01010000

01015800

<10

<10

01030500

<10

01022500

<10

01031500

<10

<10

<10

01052500 01047000

01055000

<10

01057000

<10

<10

01060000

01038000

<10

01064500

<10

01054200

Base from U.S. Geological Survey

digital files, scale 1:2,000,000

projection UTM, zone 19

<10

<10

CANADA

NEW HAMPSHIRE

CANADA

ATLANTIC OCEAN

Figure 16. Regional recurrence intervals for 7-day low flows in Maine during 2000.
22 Drought Conditions in Maine, 1999-2002: A Historical Perspective

44 o

43 o

o

o 45

71

46 o

67 o

70 o

69 o 68 o

47 o

0

0

40

50

80 MILES

100 KILOMETERS

EXPLANATION

01010000 Streamflow-gaging station and identification

number. Lower number is recurrence interval,

in years, for 7-day low flows during 2001

[<, less than; > greater than]

Regional recurrence interval

20

01047000

10

01014000

20

01010000

01015800

15

10

01030500

65

01022500

>100

01031500

30

45

<10

01052500

01055000

60

01057000

35

10

01060000

01038000

35

01064500

30

01054200

Base from U.S. Geological Survey

digital files, scale 1:2,000,000,

projection UTM, zone 19

10-60

60->100

10-60

<10

10

CANADA

NEW HAMPSHIRE

CANADA

ATLANTIC OCEAN

Figure 17. Regional recurrence intervals for 7-day low flows in Maine during 2001.
Comparison of 1999-2002 Drought to Historical Droughts in Maine 23

44 o

43 o

o

o 45

71

46 o

67 o

70 o

69 o 68 o

47 o

0

0

40

50

80 MILES

100 KILOMETERS

EXPLANATION

Streamflow-gaging station and identification

number. Lower number is recurrence interval,

in years, for 7-day low flows during 2002

[<, less than; >, greater than]

Regional recurrence interval

01014000

55

55

01014000

>100

01010000

01015800

<10

15

01030500

10

01022500

>100

01031500

>100

>100

40

01052500 01047000

01055000

40

01057000

35

<10

01060000

01038000

30

01064500

75

01054200

Base from U.S. Geological Survey

digital files, scale 1:2,000,000

projection UTM, zone 19

30-100

<10-30

>100

30-100

10

CANADA

NEW HAMPSHIRE

CANADA

ATLANTIC OCEAN

Figure 18. Regional recurrence intervals for 7-day low flows in Maine during 2002.
24 Drought Conditions in Maine, 1999-2002: A Historical Perspective

a part of the multi-year drought period because the 

ground water still was rising back up to normal levels 

during these years. 

Annual Recurrence Intervals of 7-Day SurfaceWater Low Flows

All identified historical drought periods either 

were severe in one region of the State or moderately 

severe statewide (table 6, fig. 19). The recurrence 

intervals of the lowest annual 7-day low flows during 

the drought period are shown in figure 19 (for example, 

if one region of the State had a 100-year drought in one 

year and another region had a 100- year drought the 

next year, a 100-year drought is mapped for both 

regions for that 2-year period). Stations in figure 19 

that do not have a recurrence interval associated with 

them also did not have sufficient years of record to be 

included in that particular drought period. Both the 

average and the range of recurrence intervals for the 7-

day low flows were calculated for the multi-year 

drought periods identified below (table 6). The range 

of recurrence intervals is the range of 7-day low recurrence intervals across all stations analyzed statewide 

for each drought period. The average recurrence 

interval is the average of the recurrence intervals of the 

lowest 7-day lows during the drought period at each 

station. To calculate the average recurrence intervals, 

values of 10 and 100 were used for stations listed with 

recurrence intervals of “less than 10” and “greater than 

100”, respectively. 

The periods of statewide hydrologic drought that 

were most severe were 1947-50 and 1999-2002. These 

periods had greater than 100-year recurrence intervals 

at at least three stations across the State, and 50- to 100-

year recurrence intervals in additional parts of the State 

(fig. 19). The period from 1999 to 2002 seemed to be 

slightly more severe statewide than the period from 

1947 to 1950, however the period from 1947 to 1950 

omits three stations that did not have records during 

this period. Additional years of severe statewide 

drought included 1963 to 1969, and 1995. The period 

from 1963 to 1969 included recurrence intervals of 70 

years, and greater than 100 years in the north and south, 

respectively, and 40 years in the coastal region, but was 

most remarkable for its duration. No other drought 

period spanned 7 years. In contrast, the single year 

drought in 1995 had some of the lowest 7-day surfacewater low flows on record for a single year; only 2002 

was more severe in terms of hydrologic drought (figs. 

18 and 19). 

There was only mild statewide hydrologic 

drought during many of the drought periods identified; 

however severe hydrologic drought often occurred 

regionally. The period 1952-1953 was driest in the 

western and northern regions of the State, 1955-59 was 

most severe in the south, and 1984-88 was most severe 

centrally. 1978 had mild drought statewide with recurrence intervals only as high as 35 years. 

Table 6. Approximate recurrence intervals for historical droughts in Maine, 1947-2002 [Recurrence interval, the 

average interval of time within which streamflow will be less than a particular value; <, less than; >, greater than] 

 * Includes any year with a 7-day surface-water low flow with a recurrence interval of at least 20 years at two stations or a recurrence 

interval greater than 40 years at any one station. 

Drought period Individual years of surface-water 

drought* Region Affected 

Average 

Recurrence 

Interval 

(years)

Range of Recurrence Intervals 

(years)

1947-50 1947, 1948, 1949 Statewide 45 <10 to >100

1952-53 1952, 1953 West & north 25 <10 to 90

1955-59 1957, 1959 South 20 <10 to 85

1963-69 1965, 1966, 1968 Statewide 25 <10 to >100

1978 1978 Statewide 15 <10 to 35

1984-88 1985, 1987 Central 20 <10 to 65

1995 1995 Statewide 40 <10 to >100

1999-2002 1999, 2001, 2002 Statewide 60 <10 to >100
Interaction Among Precipitation, Surface Water, and Ground Water During Drought 25

Ground-Water Levels at Middle Dam, Lower 

Richardson Lake, Maine

Monitoring wells in Maine generally only have 

from 15 to 25 years of record, making it difficult to 

establish long-term trends. The companion wells at 

Middle Dam, Lower Richardson Lake, well numbers 

OW 400A and OW 400 with a combined period of 

record of 57 years, make it possible to place the most 

recent drought years into historical context. Monthend ground-water levels at Middle Dam were graphed 

against historical maximums, minimums, medians and 

75th and 25th quartiles for the periods of drought identified above (figs. 20-27). 

Month-end ground-water levels at Middle Dam 

in western Maine fell slightly below normal in April 

1947 and September 1949 to January 1950, but otherwise were close to the median during the 1947-50 

drought (fig. 20). Similarly, ground-water levels were 

predominately in the normal range during the 1952-53 

period, dipping down below normal only in the last few 

months of 1952 and 1953 (fig. 21). Except for brief 

periods during the spring of 1955, 1957 and 1959, 

month-end ground-water levels stayed close to or 

above the median during 1955-59 (fig. 22). This result 

provided further evidence that the 1955-59 drought did 

not heavily affect the central region of the State, as 

demonstrated by surface-water analyses. Groundwater levels were below normal during parts of every 

year from 1963 to 1969, and reached record low levels 

in October of 1966 and November of 1968. This period 

also can be noted for its few ground-water-level rises 

above the 75th percentile at any time during this 7-year 

period (fig. 23). Although the 1978 drought was mild 

statewide in terms of surface water, ground-water 

levels came close to record lows by the fall of the year 

(fig. 24). 

Ground-water levels at the Middle Dam well 

were close to normal from 1984 to 1988, falling below 

normal in the fall of 1984, the spring and summer of 

1986, and the spring of 1987 to the spring of 1988 (fig. 

25). During 1995, water levels fell to record lows from 

June to September (fig.26). Analysis of this well from 

1999 to the start of 2003 showed record low month-end 

values in June and August 1999; October 2000; 

September and October 2001; December 2001 to 

February 2002; September and October 2002, and 

January and February 2003 (fig. 27). This result indicates that, at least in central Maine, ground-water levels 

were appreciably lower from 1999 to 2003 than they 

were during other drought periods in the last 50 years. 

INTERACTION AMONG PRECIPITATION, SURFACE WATER, AND GROUND WATER DURING 

DROUGHT 

The interaction among precipitation, surface 

water, and ground water helps to characterize hydrologic drought. The relation among precipitation, 

surface runoff, soil moisture, stream flow and ground 

water during times of drought are illustrated in figure 

28 (Changnon, 1987). The deficits in streamflow and 

ground water both lag and attenuate the precipitation 

deficit. Ground water is the last indicator of drought 

and does not show a response to brief periods of 

recovery in the precipitation (fig. 28). 

Record lows were set in both the precipitation 

and the surface water data sets at select locations in 

central Maine in April 1999 (figs. 6,8, and 9), showing 

that surface water responded fairly quickly (weeks) to 

precipitation deficits. Although water levels in one 

well at Madison in central Maine also set record lows 

in the spring of 1999 (fig. 13), there were a couple of 

months of lag time as compared to the precipitation and 

surface-water records. Furthermore, once groundwater levels started to drop in the fall of 2001 at all 

locations, they stayed below normal through 2002 

(figs. 12-14). Surface-water recovered briefly to 

normal levels at periods during 2002 at all stations 

(figs. 8-11). 

To understand the interactions among precipitation, surface water and ground water in more than a 

general way, it is helpful to compare hydrologic parameters at one location. There are few locations in Maine 

with a precipitation-gaging station, a streamflowgaging station, and a monitoring well in close proximity to one another and each with a historical period 

of record of over twenty years. Middle Dam, near 

lower Richardson Lake in Oxford County Maine is one 

of these locations. The USGS streamflow-gaging 

station, number 01052500, in Wentworth Location, 

N.H., is approximately 10 mi away from the NWS 

precipitation gage, 175261, and USGS wells, O400 and 

O400A at Middle Dam. Additionally, Middle Dam is 

in a region that had severe drought during both 2001 

and 2002. 
26 Drought Conditions in Maine, 1999-2002: A Historical Perspective

44 o

44 o 44 o

44 o

43 o

43 o 43 o

43 o

o

o o

o

o

o o

o 45

45 45

45

71

71 71

71

46 o

46 o 46 o

46 o

67 o

67 o 67 o

67 o

70 o

70 o 70 o

70 o

69 o

69 o 69 o

69 o 68 o

68 o 68 o

68 o

47 o

47 o 47 o

47 o

0

0

40

50

80 MILES

100 KILOMETERS

EXPLANATION

Streamflow-gaging station and recurrence

interval, in years, for lowest 7-day low flow

during drought period. [See table 1 for

station identification letters; <, less than;

>, greater than]

>100

<10

<10

<10

<10

15

<10

<10

<10 <10

<10

<10

<10

<10

<10

<10

<10

<10

<10

45

70

15

25

90

>100

<10

10

>100

>100

25

15

10

<10

<10

<10

<10

<10

50 60

30

85

90

15

20

<10

15 40

<10

45

60

15

1947-50 1952-53

1955-59 1963-69

a

b

c

e

f

i h

k

l j

n

m

g

d

a

b

c

e

f

i h

k

l j

n

m

g

d

a

b

c

e

f

i h

k

l j

n

m

g

d

a

b

c

e

f

i h

k

l j

n

m

g

d

a

Base from U.S. Geological Survey

digital files, scale 1:2,000,000

projection UTM, zone 19

NA

NA NA

NA

NA

NA

Figure 19. 7-day low flow recurrence intervals for seven historical drought periods and 1999-2002 drought in Maine. 

[NA, no data available]
Interaction Among Precipitation, Surface Water, and Ground Water During Drought 27

44 o

44 o 44 o

44 o

43 o

43 o 43 o

43 o

o

o o

o

o

o o

o 45

45 45

45

71

71 71

71

46 o

46 o 46 o

46 o

67 o

67 o 67 o

67 o

70 o

70 o 70 o

70 o

69 o

69 o 69 o

69 o 68 o

68 o 68 o

68 o

47 o

47 o 47 o

47 o

0

0

40

50

80 MILES

100 KILOMETERS

EXPLANATION

Streamflow-gaging station and recurrence

interval, in years, for lowest 7-day low flow

during drought period. [See table 1 for

station identification letters; <, less than;

>, greater than]

20

<10

55

70

>100

15

>100

>100

>100

35

60

<10

40

25

10

35

15

55

15

20

25

40

20

<10

<10

<10 <10

<10

35

25

35

<10

>100

>100

65

<10

<10

<10

<10

<10

20

<10

<10

<10

10

70

25

20

<10

<10

<10 65

<10

<10

<10

35

75

1978 1984-88

1995 1999-2002

b

b b

b

c

c c

c

e

e e

e

f

f f

f

h

h h

i h

i i

i

k

k k

k

l

l l

l j

j j

j

n

n n

n

m

m m

a

m

g

g g

g

d

d d

d

a

a a

a

Base from U.S. Geological Survey

digital files, scale 1:2,000,000

projection UTM, zone 19

Figure 19 (cont). 7-day low flow recurrence intervals for seven historical drought periods and 1999-2002 drought in Maine. [NA, no data 

available]
28 Drought Conditions in Maine, 1999-2002: A Historical Perspective

02468

10121416

Jan-52

Feb-52

Mar-52

Apr-52

May-52

Jun-52

Jul-52

Aug-52

Sep-52

Oct-52

Nov-52

Dec-52

Jan-53

Feb-53

Mar-53

Apr-53

May-53

Jun-53

Jul-53

WATER LEVEL, IN FEET BELOW LAND

SURFACE

75th and 25th percentileMedian

1952-53

Maximum and Minimum

02468

10121416

Jan-47

Mar-47

May-47

Jul-47

Sep-47

Nov-47

Jan-48

Mar-48

May-48

Jul-48

Sep-48

Nov-48

Jan-49

Mar-49

May-49

Jul-49

Sep-49

Nov-49

Jan-50

WATER LEVEL, IN FEET BELOW LAND

SURFACE

75th and 25th percentileMedian

1947-50

Maximum and Minimum

MONTH AND YEAR

MONTH AND YEAR

WATER LEVEL, IN FEET BELOW LAND SURFACE WATER LEVEL, IN FEET BELOW LAND SURFACE Figure 20. Comparison of 1947-50 month-end ground-water levels to historical median, maximum, and minimum month-end ground-wat

companion wells OW 400 and OW 400A in Maine (444637070552301 and 443647070552302). [historical period of record is 1944-98]

Figure 21. Comparison of 1952-53 month-end ground-water levels to historical median, maximum, and minimum month-end ground-wate

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302). [historical period of record is 1944-98]
Interaction Among Precipitation, Surface Water, and Ground Water During Drought 29

02468

101214

Jan-55

Mar-55

May-55

Jul-55

Sep-55

Nov-55

Jan-56

Mar-56

May-56

Jul-56

Sep-56

Nov-56

Jan-57

Mar-57

May-57

Jul-57

Sep-57

Nov-57

Jan-58

Mar-58

May-58

Jul-58

Sep-58

Nov-58

WATER LEVEL, IN FEET BELOW LAND SURFACE 75th and 25th percentile Median 1955-59 Maximum and Minimum

02468

10121416

Jan-63

Apr-63

Jul-63

Oct-63

Jan-64

Apr-64

Jul-64

Oct-64

Jan-65

Apr-65

Jul-65

Oct-65

Jan-66

Apr-66

Jul-66

Oct-66

Jan-67

Apr-67

Jul-67

Oct-67

Jan-68

Apr-68

Jul-68

WATER LEVEL, IN FEET BELOW LAND

SURFACE

75th and 25th percentileMedian1963-69Maximum and Minimum

MONTH AND YEAR

MONTH AND YEAR

WATER LEVEL, IN FEET BELOW LAND SURFACE WATER LEVEL, IN FEET BELOW LAND SURFACE Figure 22. Comparison of 1955-59 month-end ground-water levels to historical median, maximum, and minimum month-end ground-water 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302). [historical period of record is 1944-98]

Figure 23. Comparison of 1963-69 month-end ground-water levels to historical median, maximum, and minimum month-end ground-water 

OW 400 and OW 400A in Maine (444637070552301 and 443647070552302). [historical period of record is 1944-98]
30 Drought Conditions in Maine, 1999-2002: A Historical Perspective

02468

10121416

Jan-78

Feb-78

Mar-78

Apr-78

May-78

Jun-78

Jul-78

Aug-78

Sep-78

Oct-78

WATER LEVEL, IN FEET BELOW LAND

SURFACE 75th and 25th percentile Median

1978Maximum and Minimum

02468

10121416

Jan-84

Mar-84

May-84

Jul-84

Sep-84

Nov-84

Jan-85

Mar-85

May-85

Jul-85

Sep-85

Nov-85

Jan-86

Mar-86

May-86

Jul-86

Sep-86

Nov-86

Jan-87

Mar-87

May-87

Jul-87

Sep-87

Nov-87

WATERLEVEL, INFEET BELOWLAND

SURFACE

75th and 25th perc entileM edian1984-88M axim um and M inim um

MONTH AND YEAR

MONTH AND YEAR

WATER LEVEL, IN FEET BELOW LAND SURFACE WATER LEVEL, IN FEET BELOW LAND SURFACE Figure 24. Comparison of 1978 month-end ground-water levels to historical median, maximum, and minimum month-end ground-water 

wells OW 400 and OW 400A in Maine (444637070552301 and 443647070552302). [historical period of record is 1944-1998]

Figure 25. Comparison of 1984-88 month-end ground-water levels to historical median, maximum, and minimum month-end ground-wat

wells OW 400 and OW 400A in Maine (444637070552301 and 443647070552302). [historical period of record is 1944-98]
Interaction Among Precipitation, Surface Water, and Ground Water During Drought 31

02468

10121416

Jan-95

Feb-95

Mar-95

Apr-95

May-95

Jun-95

Jul-95

Aug-95

Sep-95

Oct-95

WATER LEVEL, IN FEET BELOW LAND

SURFACE 75th and 25th percentile Median

1995Maximum and Minimum

02468

1 01 21 41 6

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

Jul-00

Sep-00

Nov-00

Jan-01

Mar-01

May-01

Jul-01

Sep-01

Nov-01

Jan-02

Mar-02

May-02

WATERLEVEL,INFEETBELOWLANDSURFACE 75th and 25th pe rc entile M edian 1999 -2003 M ax im um and M inim um

MONTH AND YEAR

MONTH AND YEAR

WATER LEVEL, IN FEET BELOW LAND SURFACE WATER LEVEL, IN FEET BELOW LAND SURFACE

0

2

4

6

10

14

8

12

16

Figure 26. Comparison of 1995 month-end ground-water levels to historical median, maximum, and minimum month-end gro

Geological Survey wells OW 400 and OW 400A in Maine (444637070552301 and 443647070552302). [historical period of reco

Figure 27. Comparison of 1999-2003 month-end ground-water levels to historical median, maximum, and minimum month-end ground-w

Survey wells OW 400 and OW 400A in Maine (444637070552301 and 443647070552302). [historical period of record is 1944-98]
32 Drought Conditions in Maine, 1999-2002: A Historical Perspective

In order to determine the interaction between 

ground water and surface-water at this location over 50 

years, annual minimum month-end ground-water 

levels, and annual 7-day surface water lows are shown 

with identified periods of hydrologic drought (fig. 29). 

This relation shows the interaction between the ground 

water and surface water for multi-year periods. The 

1955-59 drought is not highlighted because it was a 

regional drought affecting primarily southern Maine. 

Low annual minimums in both the ground water and 

surface water match periods of drought in 1949, 1953, 

1964, 1968, 1978, 1984, 1987, 1995, 2001, and 2002. 

In many cases, the annual surface-water minimum 

preceded the low ground-water level by a year, such as 

in 1952-53 and in 1960-61. There also were cases, 

such as in 2000, where the surface water recovered, but 

the ground-water levels continued to fall, leading to 

extremely low surface-water and ground-water levels 

in 2001 and 2002. Years such as 1975 had low groundwater and surface-water minimums, but were not in an 

established drought period. In these cases, the drought 

was a local condition, and was not evident at other 

stations in Maine. 

Record lows during 1995, 2001, and 2002 in 

annual minimum ground-water levels and surfacewater flows could be due in part to a downward trend 

shown in the last 10-15 years. Downward trends in the 

data indicate that it probably is most appropriate to 

examine these data compared to the data immediately 

surrounding them, as opposed to over the entire period 

of record and to be cautious about conclusions made 

with the data. To examine the interaction among 

precipitation, surface water, and ground water more 

closely during the 1999-2002 drought, departures from 

monthly mean data for all three data sets were normalized and plotted for the sites near Middle Dam, Maine 

(fig. 30). The departure from the mean for each month 

was calculated as the difference between the monthly 

mean and the long-term monthly mean, divided by the 

long-term standard deviation for that month. A positive value indicates above-normal conditions and a 

negative value indicates below-normal conditions. 

The sites at Middle Dam show the lag of groundwater response to precipitation as compared to surface 

water response to precipitation. For 1999, the precipitation gage shows its lowest dimensionless departure 

from the monthly mean in April, whereas the lowest 

departure from the monthly mean for the year was in 

May for surface water and August for ground water 

(fig. 15). Even in months at the end of year 2000 and 

the beginning of 2001, when precipitation was above 

normal and surface water rose to above normal at 

times, the ground-water level did not rise back to 

normal. This lack of recovery indicates that groundwater responded more slowly than surface water to 

precipitation, and that the drought may have extended 

through the moderately dry year of 2000 in the ground 

water at this location, as indicated in figure 29. 

Another example of the lag of ground-water levels in 

response to precipitation is shown in 2001. Although 

precipitation was consistently at or below the monthly 

mean starting in the spring of 2001, ground-water 

levels did not reach record lows until the fall, when 

precipitation was starting to recover. Surface water 

responded and recovered more quickly during this 

period. 

SUMMARY AND CONCLUSIONS 

Dry conditions were present in Maine from 1999 

to 2002, with a severe drought in 2001-2002. Hydrologic drought, defined as reduced streamflow,

Figure 28. Precipitation deficits propagated in runoff, soil 

moisture, streamflow, and ground water over time (from: 

Changnon, 1987). [Dashed lines link precipitation deficit to 

deficits in other hydrologic indicators]
Summary and Conclusions 33

YEAR

west & north central

Periods of statewide hydrologic drought

USGS monitoring well 443647070552302

USGS streamflow-gaging station 01052500

Periods of regional hydrologic drought and area of influence

WATER LEVEL, IN FEET BELOW LAND SURFACE

1945

1947

1949

0

2

4

6

8

10

12

14

16

1951

1953

1955

1957

1959

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

Figure 29. Annual minimum month-end ground-water levels and annual 7-day surface-water lows plotted with periods of surface-wate

Lower Richardson Lake, Maine, 1945-2002. [1955-59 not shown as period of drought because it did not affect the central region of State]
34 Drought Conditions in Maine, 1999-2002: A Historical Perspective

-5-4-3-2-1

01234

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Jan-00

Mar-00

May-00

Jul-00

Sep-00

Nov-00

Jan-01

Mar-01

May-01

Jul-01

Sep-01

Nov-01

Jan-02

Mar-02

MONTH AND YEAR

DEPARTURE FROM MONTHLY MEAN, DIMENSIONLESS USGS monitoring well 443647070552302 (1944-2002) USGS streamflow-gaging station 01052500, Diamond River near W entworth Location, N.H. 

NWS precipitation station (1948-2002)

Breakin record

Figure 30. Precipitation, surface water, and ground water departures from monthly means near Middle Dam, Lower Richardson Lake, Main

US Geological Survey; NWS, National Weather Service]
References Cited 35

declining ground-water levels, and (or) reductions in 

lake or reservoir levels, is a temporary aberration, relative to some long-term (tens of years) average condition, and is a normal, recurring feature in all climatic 

regimes. This report, prepared by the US Geological 

Survey, presents precipitation, surface-water, and 

ground-water records compared to historical statistics 

to give an overall picture of the drought years 1999-

2002 in Maine, and to put these recent years into 

context with historical droughts. Little work has been 

done previously in Maine that integrates these records 

during periods of extreme low flow. 

Examination of precipitation, surface-water, and 

ground-water records across the State helped to characterize the most recent period of drought. Record lows 

were set in all three data sets at select locations in 

central Maine in April 1999. Although the surface 

water recovered at most locations during 2000, groundwater levels in the central region did not recover. Low 

water levels could have been carried over into 2001 

when the central region had surface-water recurrence 

intervals greater than 100 years. The drought spread 

north and west in 2002 with record lows being set in 

both of these regions in the fall of 2002. Initial examination of the interaction among precipitation, surface 

water, and ground water at one location in 

central/western Maine indicated that streamflow 

responded fairly quickly to below-normal precipitation 

across Maine in 1999 and in 2001-2002. Streamflow 

also recovered fairly quickly in between these periods 

(during 2000). Ground water was slower to respond to 

low levels of precipitation and slower to recover than 

streamflow, with a potential lag time of up to one year. 

Study results show that 1999-2002 was the most 

severe drought on record in Maine based on statewide 

7-day annual surface-water low flows and one 

ground-water record in central Maine. The period of 

record was approximately 50 years across stations. 

The period from 1947 to 1950 may have been the only 

comparable period of drought statewide. The 1960s 

drought, although extreme in the northern and southern 

regions of the State, was most severe in its duration in 

the central, western, and coastal regions of the State. 

The drought in 1995 was unique in that it had some of 

the lowest streamflows statewide for a single year, 

second only to 2002. Year 2002 was the lowest single 

year on record in terms of statewide surface-water 

levels, with 7-day annual low-flow recurrence intervals 

of greater than 100 years at four locations. Other 

historical drought periods, including 1952-53, 1955-

59, and 1984-88, were severe regional droughts. A 

mild statewide drought occurred in 1978. 

Further work would be needed to quantify the 

extent to which hydrologic droughts carry over from 

year to year in ground-water levels and to determine 

the timing and amount of precipitation that was necessary to end historical droughts. The linking of hydrologic droughts with climatological droughts (for 

example percentage of normal precipitation) could 

potentially allow water-resource managers to characterize droughts while in the middle of a drought period. 

An in-depth examination of the progression of hydrologic droughts in the ground water over many years of 

record would be needed for this examination. Studying 

the interactions of ground water and surface water will 

be important to determine if assumptions can be made 

about late summer low flows based on the timing and 

the magnitude of spring ground-water levels. 

REFERENCES CITED 

American Meteorological Society, 1997, Policy statement--

meteorological drought: Bulletin of the American 

Meteorological Society, v.78, no. 5, p. 847-849. 

Bradbury, J.A., Dingman, S.L., and Keim, B.D., 2002, New 

England drought and relations with large scale atmospheric circulation patterns: Journal of the American 

Water Resources Association, v.38, no.5, October 

2002, p.1287-1299. 

Changnon, S.A., 1980, Removing the confusion over 

droughts and floods--The interface between scientists 

and policy makers: Water International, v. 5, no. 2, 

p.10-18. 

______ 1987, Detecting drought conditions in Illinois: Illinois State Water Survey Circular 164-87, 36 p. 

Helsel, D.R., and Hirsch, R.M., 1992, Statistical methods in 

water resources: New York, Elsevier, 522 p. 

Jordan, P.R., and Jennings, M.E., 1991, State summaries of 

floods and droughts, in Paulson, R.W., Chase, E.B., 

Roberts, R.S. and Moody, D.W. (compilers), 1991, 

National water summary 1988-99-- Hydrologic events 

and floods and droughts: U.S. Geological Survey 

Water-Supply Paper 2375, p. 158-162. 

Maidment, D.R., 1993, Handbook of hydrology: New York, 

McGraw-Hill, Inc. 

Maine Agricultural Water Management Advisory Committee, 2003, Growing Agriculture, Sustainable Agricultural Water Source and Use Policy and Action Plan, 

prepared for Robert W. Spear, Commissioner, Maine 

Department of Agriculture, Food and Rural Resources, 

18 p. 
36 Drought Conditions in Maine, 1999-2002: A Historical Perspective

Maine Emergency Management Agency, 2002, Drought 

Impact Research Summary Report, prepared by Vilma 

Galubickaite, Market Decisions, April 2002, 22 p. 

Maloney, T.J., and Bartlett, W.P., Jr., 1991, Maine floods 

and droughts, with a section on “General Climatology” 

by Robert Lautzenheiser, in Paulson, R.W., Chase, 

E.B., Roberts, R.S. and Moody, D.W. (compilers), 

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